Electronic signature (OpenOTP, LibreSign. eIDEasy...)

Hi

I’m looking for a tool to use electronic signature in PDFs hosted in my NC instance. I can see three options in the NC apps:

  1. LibreSign: I can’t understand how to test it since the documentation es very short, anybody has tested it? How it works? Any tutorial to make a test environment from scratch?
  2. OpenOTP: more documented that LibreSign but still lack of information. I must install a OTP Server and it’s limited to 40 users (in freeware mode) so I guess it only signs documents between NC users, but not sure, anybody has tested or is using it?
  3. eIDEasy: by far the more comprehensive app and seems the only one that has a really NC integration. But every document costs 0.50eur and a lot of things are not configurable, I would prefer a free option or, If I must pay, a more flexible app in terms of settings.

Any tip?

Thanks in advance

Interested, someone testing that solutions?