To be completed by the original poster:
I installed Xibo 3.3.2 via docker on Centos 7 and everything seems to work fine except sending emails. I filled in my mail server information in the config.env file and set up a user with MFA, but when I try to send the verification code I get an error. I’ve done a lot of tests and I don’t know what else to do. Attached are some prints of what is going on.