With the idCAT certificate installed on the computer, open the PDF with Adobe Acrobat Reader and follow the following steps:
1. Go to Tools
2. Select the "Certificates" tool block:
3. Select the "Sign digitally" option
4. Select the space where you want to insert the signature
5. Select below your idCAT certificate with which you want to sign.
6. Finally, the signature will look like this:
