Is it possible to automate the filling of available fields in pdf files?

Question

PDF

Good day.
There are a number of pdf files that come in periodically.
They have writable fields.
I would like to automate this somehow, so as not to fill in manually.
Are there any options? Maybe scripts or libraries for writing such scripts?

And if I may be interested in another question, after filling it is possible to prohibit changing these fields? Also automated.

Thanks in advance for your replies