What should I do if I want to produce an Android application and there are not many test phones?

I'm trying to make an application and test it this time, but the company doesn't have a test phone, so we can't do various tests.

I looked into it and found that people like me rent smartphones or

I heard that you can test your device freely, such as

Considering the time and money, I think it's hard to decide whether it's right to buy a test air-powered smartphone or whether it's good to make a reservation and go and test it yourself.

What do you think is better for those who experienced it first?

Or is there another way?