ENTER A or 0 for Schwarzschild radius for our sun
  0.000000000000000E+000
 MASS OF BODY - KILOGRAMS
  1.990000000000000E+030
 RADIUS OF THE SUN - METERS
   695950000.000000
 TOTAL RAY DEFLECTION IS   1.75074437282132       arc seconds official
 WIDTH OF LIGHT RAY - METERS
   655000.000000000
 TIME INCREMENT - SECONDS
  1.000000000000000E-002
   1.28462126313333       ARC SEC, DIST =           1  R
   1.59054184508388       ARC SEC, DIST =           2  R
   1.67527376422873       ARC SEC, DIST =           3  R
   1.70827290038373       ARC SEC, DIST =           4  R
   1.72421867880825       ARC SEC, DIST =           5  R
   1.73306790110479       ARC SEC, DIST =           6  R
   1.73846825118068       ARC SEC, DIST =           7  R
   1.74200061229695       ARC SEC, DIST =           8  R
   1.74443500433983       ARC SEC, DIST =           9  R
   1.74618346603163       ARC SEC, DIST =          10  R
   1.74747904551263       ARC SEC, DIST =          11  R
   1.74845208156234       ARC SEC, DIST =          12  R
   1.74921369249508       ARC SEC, DIST =          13  R
   1.74982033842731       ARC SEC, DIST =          14  R
   1.75031166156846       ARC SEC, DIST =          15  R
   1.75072850540704       ARC SEC, DIST =          16  R
 TOTAL RAY DEFLECTION IS   1.75072850540704       ARC SEC

* TOTAL RAY DEFLECTION IS   1.75074437282132       arc seconds official for standard model
* in 12/5/2023 I get defl   1.75072850540704       arc seconds using 2GM/c^2 M=sun mass
* bending of light around the sun using epi = epi0*(1+A/R)**2 bending  Dec 5, 2023
* Ray starts at the sun and leaves the sun.
* The angle of departure is doubled to get the total angle for both arrival and departure angles.
* X0 Y0 IS ON THE SURFACE OF THE SUN, X1 Y1 IS FARTHER OFF THE SURFACE
      IMPLICIT DOUBLE PRECISION (A-H,L-Z)
* the 4000 here results in a distance away from the Sun of 8 diameters
      PRINT *,'ENTER A or 0 for Schwarzschild radius for our sun'
      READ *,A         !
      PRINT *,A
      G=6.67D-11
      PI=3.14159265D0
      Co=2.998D8
      EPI0=8.85418783D-12
      MU=4.*3.14159265D-7
      PRINT *,'MASS OF BODY - KILOGRAMS'
      M=1.99D30
*      READ *,M
      IF(A.LE.0.) A=2*G*M/Co**2        ! Schwarzschild radius formula
      WRITE(*,*) M
      PRINT *,'RADIUS OF THE SUN - METERS'
      Radius=695950.D3
*      READ *,Radius
      WRITE(*,*) Radius
* below is a check for the bending around the sun using an official calculation
* TOTAL RAY DEFLECTION IS   1.75074437282132 arc seconds official due to general relativity
* REL13  RAY DEFLECTION IS  1.75072850540704       arc seconds using 2GM/c^2 M=sun mass
      ANG=(4.*G*M/Radius/Co**2)*360.*3600./2./PI   ! official answer to the angle
      PRINT *,'TOTAL RAY DEFLECTION IS',ANG,' arc seconds official'
* this width of the beam produces the same bending as the exact formula
      W=655000.D0
    3 PRINT *,'WIDTH OF LIGHT RAY - METERS'
*      READ *,W
      PRINT *,W
* ~750,000 km radius in ~2.5 sec.  if there are 250 steps each radius distance time, .01 sec each step  then 4000 of these
* is a total time of 40 sec or 4000/250 = 16 radius's or 8 sun diameters the wave travels
      TI = .01D0
      PRINT *,'TIME INCREMENT - SECONDS'
*      READ *,TI
      PRINT *,TI
* the angle must be small and the ray is at Y0 bottom of the ray which is traveling along X to the right
      Y0=Radius
      Y1=Radius+W
* .01 sec per interval produces a TT total time of 40 sec or 16 times the radius of the Sun
      TT=0.D0
      X0=0.D0
      X1=0.D0
      DO 1 I=1,4000
* ray travels in X direction only and assume change in Y is negligible (this is an approximation, good only for very small angles)
      R0=DSQRT(X0*X0 + Y0*Y0)
      R1=DSQRT(X1*X1 + Y1*Y1)
* formula EPI = EPI0*(1+A/R)**2 is tested
* deviation in distance with respect to 0
      EPI = EPI0*(1.D0+A/R0)**2
      X00 = TI/(DSQRT(MU*EPI))
      EPI = EPI0*(1.D0+A/R1)**2
      X11 = TI/(DSQRT(MU*EPI))
* remember the distance traveled by the two rays as we move away from the sun
      X0=X0+X00
      X1=X1+X11
* XD is the difference in the small deviations, note that subtraction above is reflected in the reverse of the subtraction below
      XD=X1-X0
      IF(I/250*250.EQ.I)
     &  PRINT *,2.D0*360.D0*3600.D0*XD/(2.*PI*W),
     & ' ARC SEC, DIST =',I/250,' R'
    1 CONTINUE
* the factor of 2 is to include both approach and leaving of the wave, i.e. double the leaving angle
      ANG=2.D0*360.D0*3600.D0*XD/(2.*PI*W)
      PRINT *,'TOTAL RAY DEFLECTION IS',ANG,' ARC SEC'
*      IF(W.GT.10.) GOTO 3
      STOP
      END

An executable for this program is posted here:
https://egpreston.com/REL13.exe  and it's not a virus.
If successfully downloaded put it in a folder where you can open a command prompt window
and type dir to make sure you can see the REL13.exe file and then type REL13.exe and it
will run the program and you can see the results are the same as at the top of this file
if you enter 0 for the value of A.  Or you can copy the program and use your own compiler.