What I said.
He can spend bucks appropriated and authorized for a purpose as defined in the PB.
I am sorry I may be misunderstanding. DOD discretionary funds not allocated to a specific project can be diverted by the President as the CINC. He does not need congressional approval for that. Those funds are allotted as part of the budget annually for the DOD and the CINC to utilize for such things as extended deployments, cost overruns etc.. Those are the funds Trump already spent, the $5 million. Congress allocated (I believe) $10 or $15 million in the current DOD budget for “border security.”