Call 911 and call reception. See if I can help in any other way by knocking/banging on the door.

999 and probably bang at the door.

Knock their door. Depending on reaction I call the reception desk and/or police.

I'd reach the hotel's reception and tell what I heard

Try to reach hotel staff and tell them, while readying the moves I learned from kung fu panda

I'd call reception with my concerns unless I was 100% adamant what I was hearing was abuse (it could be hard in context). If I was sure of what I was hearing I'd bang hard on the door and shout at the guy to try and hit something his own size.

Bruhhh I'm a petite woman, I'll call the police, won't risk myself barging to help.

I'd beat on their door, make noise and hopefully distract any attacker while I'm on the phone getting some help (I'd call the hotel before the police if only because they are already on site, also cops are not to be trusted)