Usually you can find examples at File > Examples > Wire. Make sure to select your STM32 board from the Tools > Board menu first to be sure that the examples for that board's specific Wire library are loaded.
It's difficult to provide specific information without knowing which hardware package you're using to add support for your blue pill (there are at least two different ones if I remember correctly and I'm not going hunting for them). Please post a link to the one you're using.