Initialise msg.payload after deploy

where did node-red save it variables? each time i deploy my project. i found that msg.payload doesn't be initialed in mytemplate? i have cleared my navigator cache, i have been search a lot wich file cantains saved variable but without results.!!!
Can anyone explain to me this ?

Unless you set up file-based retention, variables are stored only in memory. That means that if you restart Node-RED or do a full deploy, everything is reset.

Partial deploys may not reset some variables.

It is all in the docs.

and msg.payload is sent to your template by the previous node and wouldn’t be saved.
You can save certain variables (context variables) between node-red restarts as explained in the docs, but you would have to then add them into your flow rather than expect a template looking for msg.payload to know about them.