How to read and parse object names in node-red?

I want to read and use Xjlp10Vdamd5HrZWYTwJeFMrGrh2, koglQNzQT5WNtYNXBKi3clqi9T52, null from msg.payload or create another msg.payload, how do I do it?

Depending on what your exact requirements are, you can do this with jsonata in a change node.
Example:

It is easier to get help here if you supply the input data (as text) and the expected output format.