Currently it doesn’t seem to support force Bitlocker with PIN by Intune. The BitLocker policy must not require use of a startup PIN or startup key. When a TPM startup PIN or startup key is required, BitLocker can't silently enable and requires interaction from the end user.
Reference: https://video2.skills-academy.com/en-us/mem/intune/protect/encrypt-devices#silently-enable-bitlocker-on-devices
Some end users have already post such request in Intune UserVoice, I think you can vote the following ticket to address this issue. Many features of our current products are designed and upgraded based on customer feedback. We strive to capture any negative reviews in order to ensure that we are continuously improving our products to meet our customers' needs. With your efforts, we are committed to improving our products. Here is the link:
https://microsoftintune.uservoice.com/forums/291681-ideas?query=Bitlocker%20with%20PIN