Taking old fridge out of RV. New one does not use gas. how do I cap the propane line that ran to the old fridg?

You have to do some detective work and follow the gas line back to the manifold connection, remove the line and cap it off at the manifold make sure once you install the correct cap with pipe dope on it you then check the system with soapy water and make sure you have no leaks.Good Luck