Finally, After several attempts, the application worked successfully... in order to do so, I did the following:

1 Delete the fonts section from the sys.txt
2 copied some Arabic files to the ui_nextgen/font folder in addition to the files that were previously there
3 Add the line (font="ui_nextgen\fonts) to the Folders section of the sys.txt

In this case, I think that the application itself chooses the appropriate font, whether Arabic or English

It was not so easy because I needed to go to my car and go back again several times for test

Thank you so much brother LouBouha without your guidance I would not have this result. I appreciate your effort with me and wish you happy times.