TCL inverter aircon: bakit walang water draining?

Just bought a TCL TAC 09CWI UJE. Using it for maybe a week now.

We hear a sloshing sound from time to time but partner's been curious why walang drip sa likod. Inaabangan nya talaga. Hindi nababasa yung lapag sa likod.

I only saw one relevant article about this but I want to be sure. Baka may mga nakakaalam dito. Sabi sa article hindi sya need idrain.

Is this normal? Should I leave it alone?

Manual says none about it.

Thank you, mafriends 🤘🏽