Deployment of the National Guard within a state is at the discretion of that state's governor. DC is the only place the president has jurisdiction in this scenario.
https://apnews.com/article/national-guard-los-angeles-immigr...
It's now winding its way through the appeals process.
Legally, there are exceptions to that (primarily the Insurrection Act, though there are some deployments that are permitted within states on federal authority on other legal bases with tightly-constrained functions), and practically, the legal limits don't matter because response time off the courts is to slow for them to act as a meaningful brake. (E.g., the lawsuit filed the first court day after the order to mobilize the guard for LA just reached the trial stage this week.)
But critically, the trial in which the legality of that action is considered is happening the week. Whether or not the action is judged to have been a constitutional violation ultimately doesn't matter; the administration did it, and even if the court rules against the administration, it will have been two months too slate. Effectively, the president has demonstrated he can federalize the national guard whether or not the governor consents for long enough to score whatever political/media points he's currently fixated on, and if the legal system stops him, he will have moved on to other issues.
https://apnews.com/article/california-trump-national-guard-l...
Pretty sure that doesn't apply in LA in 2025.