Why is my iPhone only sending texts as SMS and not iMessage?

Jablet wrote:

I did check that actually, unforutnately it doesn't explain why I'm recieving some as SMS while others are imessage. Another issue I probably should've stated is my imessage send and recieve keeps toggling on and off, then takes forever for waiting for activation or doesn't activate at all

Read here If you can't send or receive messages on your iPhone or iPad - Apple Support

Follow steps on can't sign into imessage/facetime.

Jablet wrote:

This has been a weird issue, and I can't to find anything on it. I had a werid thing where my messages wouldn't activate at all. I have gotten a new phone, physical sim to eSIM, and I'm good. Some messages are still failing to send to me, but where is werid is my messaging. I am recieivng imessages, but for some reason my phone is only sending as SMS. Any thoughts on why this is happening as well as how to fix.

[Re-Titled by Moderator]

Read here If your iPhone messages are green - Apple Support