Reg key on google play

Im trying to figure out how some apps on google play have you download the free
version and they have another listing on google play that just installs the key part
that unlocks the features in the free version .

is this possible with Kodular .

Im tired of keeping up with 2 projects paid and free.

Create 1 app with all the features.

Enable some of those features so everyone can use them.

Use an IAP to unlock the remaining features.