Yep, it supports ACME (Let's Encrypt) out the box and many DNS providers too. I mainly use namecheap as my registrar but configure Cloudflare as my DNS resolver; I find this easier from a configuration perspective and CF APIs have been stable for me so far.

Traefik (by default) will attempt certificate renewal 30 days before expiry. Perhaps the defaults will change if the lifetime becomes 45 days. I don't think it's possible to override this value, without adjusting the certificate expiry days, but I've never felt the need to adjust it.