Can you end a sentence with a preposition?
Yes, it’s fine to end a sentence with a preposition. The “rule” against doing so is overwhelmingly rejected by modern style guides and language authorities and is based on the rules of Latin grammar, not English.
Trying to avoid ending a sentence with a preposition often results in very unnatural phrasings. For example, turning “He knows what he’s talking about” into “He knows about what he’s talking” or “He knows that about which he’s talking” is definitely not an improvement.