iOS App error: untrusted Enterprise Developer

I download iOS app my iPhone showing some errors, how to solve this error please help me

See
https://docs.thunkable.com/thunkable-cross-platform/download#to-install-trust-thunkable-on-your-device

I new for developing what is the “business name of thunkable”

Rappidly Inc., it says right here

On your first time downloading apps for iOS, you will need to open your Settings app, navigate to General and Device Management and then Trust “Rappidly Inc” (the business name of Thunkable)

Ok Thank you…