Node red opcua server help

hi all, i'm starting writing a node red code with opcua server package. I need comunicate in read and write mode many variables with client: arrays strings, char, int and many other and I need capture when client change some parameters.
can someone explain me how opcua can be set to do that? can someone explain me how to set variables?
many thanks in advance

(maybe a detailed tutorial exist? online I found video or example but I could extract information i need) for example i can create an opcua server in nodered and connect to it with a client but I need details to set variables which server and client read and write

many thanks again
best regards