My IPhone 7 is locked to sprint and i can't get passed the activation screen without a sim card?

I'm currently with cricket and my sim card reads as "SIM NOT SUPPORTED" is there any way to bypass this screen? Or a a sim adapter(if any on amazon) to use my cricket sim on the iphone and finally do the activation. And be able to access the homescreen

You need a working SIM, just for a few minutes. There's no other way of doing it.

All you need is to borrow one from another phone until the activation is complete then swap it back.

The phone will still need unlocking from Sprint [by Apple, via a service provider] before it will work with another network, though, unless that's already been done and its just not been able to update itself yet.

The easiest way is usually use a pre-pay SIM on whatever network the phone is locked to. Once it's been registered to you and working for a couple of weeks, the company should accept an unlock request & you can then switch to whichever service you like.

You must go directly to sprint to get it unocked there are ways online but it can get expencive and not all of them support sprint