Grammar fix
I'd like to check in
request check-in
A polite, standard way to tell airport or hotel staff that you want to register your arrival.
expressionB1common
Hear it in context
Notice where the phrase sounds natural.
Hi, I'd like to check in for the nine o'clock flight to Rome.
A: Good morning, how can I help?
B: Hi, I'd like to check in, please.
Fix the pattern
One small grammar move makes it sound right.
Not: I want check in.
Say: I'd like to check in, please.
Use 'I'd like to' + verb for a polite request, and keep the 'to': not 'I want check in'.