Buckle up

Buckle up
Buckle up" is a straightforward phrasal verb with a clear literal and metaphorical significance. Literally, it refers to fastening one’s seatbelt in a vehicle. Figuratively, it can mean preparing for a difficult or exciting experience. Before embarking on a turbulent flight or venturing into a challenging project, you might hear someone advise you to "buckle up," implying "prepare yourself.
Don't forget to buckle up!
buckle up means to fasten a seatbelt
She always buckles up her seatbelt.
she always fastens her seatbelt
Buckle up for the long journey ahead.
prepare yourself for a long journey ahead