The president has broad authority to take military action without the requisite congressional authorization for up to 60 days (plus another 30 to allow for withdrawal of troops). It's been this way since the War Powers Act of 1973.
https://www.congress.gov/107/plaws/publ40/PLAW-107publ40.pdf
—Consistent with section 8(a)(1) of the War Powers Resolution, the Congress
declares that this section is intended to constitute specific statutory
authorization within the meaning of section 5(b) of the War Powers
Resolution.