I like to use MColorpHast strips. They are meant for liquids. But you can get an approximate reading by putting in soil, wet with distilled water. Wait 3-5 minutes and read strip. It’s not super accurate but gives you a ballpark number. Funny you mention pH as I was going out to test my blueberries when I saw your post.
So I tested Spartan blueberry near the trunk. Notice the white strip buried halfway.
Reading is about 5.3. I use the 4.0 to 7.0 strips. Easy to read.
I tested tap water and reading is 7.0 which tells me it’s too basic.
These are industrial grade strips. Strips are plastic. You can probably find other companies that make them on Amazon.
I bought mine from this site but they are kinda expensive. Look on Amazon for better prices.