Automatically populate SEGMENT with contacts in TAGS - Mautic 4

My Mautic version is: 4.0.1

I need to populate a segment with new contacts added to TAGS in mautic 4.

I integrated mautic with an affiliate platform that saves new leads emails in mautic 4 Tags.

I need to understand how to send an email automatically immediately after they sign up…

I think that maybe there should be some way of automatically copy new tags contacts to a segment in order to send an email to my lead as soon as he signs up.

Is it possible to do this? I can not find any mautic 4 documentation using tags…

If this automatic population from tags to segments is not allowed, how can I send an email immediately after a contact is added to tags? any hint?

Click segments - new - filter selects tags - select the tag you want to use. Save