Phone number cannot be used for iMessage and FaceTime

Hello, recently i wanted to set up iMessage after quite some time of owning an iPhone. I added my number to my apple ID and it says that i need SIM associated with an apple device for my number to be used for iMessage and FaceTime. I dont understand, i use a physical SIM and its inserted so why is it not associated with an apple device? Ive tried restarting my phone, reentering my phone number, taking my sim in and out, and im 100% sure the phone number im entering is correct because ive had it for years as i said even before having an iPhone. I dont know if its related but when i go into ‘phone’ in the settings i cant edit ‘my number’