Saving IDs of certain blocks?

Previously, the block instance id was saved when the server was restarted, it is now changing. How can I keep the identifiers of certain blocks when the server restarts?

 

help me pls=)
I will give my example
I put the foundation it assigns an identifier through the entity.GetInstanceID ()
After rebooting the server command, the foundation changes its ID to another

 

Everything, fixed
Thx, all=)

 

Just in case you're using something else, I found it's best to use the entity's net ID.

 

Yes, I use it, thank you.