When using SASL EXTERNAL, TLS is required

I tried to disable tls on Libera and got this message:

Config file error:

• TLS is not enabled for 'palladium.libera.chat', but SASL EXTERNAL authentication requires TLS. Please enable TLS for this server in the config file.

I would like to know why is this necessary and if there's a way to fix this, because sometimes it is necessary to have EXTERNAL SASL without TLS. Ex: if I'm using I2P or Tor the domain will not have a valid certificate.

[trevarj]

See my comment here