The Attiny85 doesn't have a UART so it will require using software to emulate the serial interface needed to interface with a Bluetooth module. But you should be okay with a 433 MHz module as those usually come with a single data line. I think your main issue is programming the module via emulated USB CDC. You can solve this right away if you have a proper programmer that doesn't require a software running on the Attiny85 to program. In my honest opinion, every Arduino user should have at least one. Try searching for USBtinyISP online
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