Congress has no role - zero - in EO 13526 secition 3.1 Declassification. There is one procedure involving DNI, but "plan B" is:
"In some exceptional cases, however, the need to protect such information may be outweighed by the public interest in disclosure of the information, and in these cases the information should be declassified. When such questions arise, they shall be referred to the agency head or the senior agency official. That official will determine, as an exercise of discretion, whether the public interest in disclosure outweighs the damage to the national security that might reasonably be expected from disclosure. "
That "agency head" would be Sessions.
Activate ]SESSIONS[.
Hence AG Sessions letter to SC 1&2 (Roberts and Thomas?) for clarification, and also Roberts runs FISC, which controls the FISA memo.