During its brief and utterly failed attempt to reduce its balance sheet (called quantitative tightening), the Federal Reserve only rolled off securities at a rate of $50 billion a month. It is now purchasing US treasuries at a rate of more than $55 billion a month:
The Federal Reserve continues to add more US government securities to its securities portfolio and these have been bought outright…. Since January 1, 2020, the Fed has added $113.7 billion to its securities portfolio.
Seeking Alpha
Buying securities outright is called "monetizing the debt" because the Fed creates money