Try it.
You probably can’t do it through HAL calls because it’s such an unlikely desire.
I suggest you look in the References Manual for how to select Alternate Functions for the GPIO pins. And the Data Sheet for which AltFunction number you need for USART1.
I don’t know if it will work. It depends on the detail of how ST chose to implement the AltFunction circuits, and might differ between stm32 families. (A reason it might not work is if ST chose to prevent inputs from being abused in the same way).
Hope this helps,
Danish
