Become my own SIP trunking Provider

I have some VOIP phones and an Asterisk PBX. I want to make my own SIP trunking and maybe sell SIP Trunking ligne. I looked online, but I didn’t find the steps to make my own SIP trunking, just book, and courses about SIP trunking.

Also, I will probably use an SBC as well.

How could I make my own SIP trunking? Do you have some suggestions or books that you recommend me?

Thanks