What are you talking about?
The legal system isn't telling the executive branch how to "deal with El Salvador." The legal system handles deportation/asylum cases. It made 2 rulings on Garcia and the executive branch defied both. The first that he couldn't be deported to ES (this was during Trump 45) and the 2nd to facilitate his return.
Here's where we would be in some agreement. If El Salvador asks the US to extradite someone who fled to the US, then, yes, the court cant keep him here. The argument would then become should we extradite an ES National, who has no criminal record in either country for a life sentence with no due process in that country? That's a moral/humanitarian debate, not a legal one. If the ES asks to extradite, the US State Dept can do so.
You aren't paying attention.
From AP:
"A federal judge on Wednesday said he’ll order the Trump administration to provide more information about the terms under which dozens of Venezuelan immigrants are being held at a notorious prison in El Salvador, moving a step closer to deciding whether to require the men to be returned to the United States.
District Court Judge James E. Boasberg said he needed the information to determine whether the roughly 200 men, deported in March under an 18th century wartime law, were still effectively in U.S. custody. Boasberg noted that President Donald Trump had boasted in an interview that he could get back one man wrongly imprisoned in El Salvador in a separate case by simply asking. The government’s lawyer, Abishek Kambli, said that and other public statements by administration officials about their relationship with El Salvador lacked “nuance.”
Kambli would not give Boasberg any information about the administration’s deal with El Salvador’s President, Nayib Bukele, who once called himself “the world’s coolest dictator” and is holding immigrants deported from the U.S. at his country’s CECOT prison. He would not even confirm the terms of the deal, which the White House has said are a $20 million payment to El Salvador."
From the Independent:
"Following the Supreme Court’s order, Judge Xinis ordered daily updates on Abrego Garcia’s condition and the steps the government is taking to “facilitate” his release.
But administration officials have publicly claimed that the Supreme Court’s ruling said no such thing, and government lawyers in court documents have raised a series of arguments to avoid answering, including attorney-client privilege and “state secrets” privilege
“The State Department has engaged in appropriate diplomatic discussions with El Salvador regarding Abrego Garcia,” Justice Department lawyers wrote earlier this month. “However, disclosing the details of any diplomatic discussions regarding Mr. Abrego Garcia at this time could negatively impact any outcome.”
Judge Xinis said she “requires specific legal and factual showings to support any claim of privilege.”"
