Hello. Your English is far better than I can speak whatever your
native language is. Don't worry about it, please. As long as we can
understand each other, we're good. What's your name?

As to your problem, I rather suspect that your form is in protected
mode. You should save it in order to disable that. I recommend saving
it to a different name than the original, so you'll always have that 1
as a backup in case the form you're working with somehow gets messed
up (it happens). Also, when you do save it, the computer will want to
save it to a temporary folder. Browse to your documents folder or
another of your choosing & save it there instead.

Then you can use the tab & shift-tab key to fill in the fields.

Please let me know if my instructions are clear &/or if they help.
Good luck & much success on your thesis.

--
Remember! Friends Help Friends Be Cybersafe
Jackie McBride
Helping Cybercrime Victims 1 Person at a Time
https://brighter-vision.com