Check out

chequearse de

(to pay when leaving)

documentarse de

(to pay when leaving)

escanear los ítemes

(to record someone as leaving)

facturarse de salida

(to pay when leaving)

pagar la cuenta

(to pay when leaving)

registrar la salida

(to record someone as leaving)

registrarse la salida

(to pay when leaving)

retirarse

(to pay when leaving)

sacar

(to withdraw (an item) from a library etc., and have the withdrawal recorded)