I was testing to connect to Twilio services to send SMS from ignition but when creating the connection I got this error.
Do I need to modify something? In the connection configuration I only put the username and password that the Twilio page gave me
Copying my post from another unrelated post with likely the same root cause:
This means the root CA that signed the certificate of the endpoint you're talking to is not trusted. If this is a public website then it probably means you're on a corporate network that is proxying/MITMing your traffic and inserting its own CA, in which case you need to add that CA to Ignition's supplemental certificate store: Security Certificates - Ignition User Manual 8.1 - Ignition Documentation
I am not very related to the issue of certificates, do I need to get the twilio certificate? How could I do that?
No, Twilio certificates are signed by a public CA that would be trusted by default.
You probably need to talk to your IT department to get the corporate root CA being used to intercept traffic, if that's what's actually happening.