So Spotrac has him as an ERFA, while OTC has him as an RFA. The cutoff between ERFA and RFA should be three accrued seasons.
He spent all of 2019 on IR, which DOES count as an accrued season.
2021 would also have been an accrued season
The question for me is 2020. If I read the NFL's language, he would needed to have been on the active 53 man, or on IR, for at least six games, in order to qualify. Based on what I can tell, he was only on the 53 man for two games in 2020 (week 14 and 15), he spent the first 13 weeks prior to that on the Practice Squad (does not count towards accrued seasons from what I can tell), and then reversed back to the P/S after two games.
So the way I read this, he should have 2 accrued seasons, which makes him an ERFA, instead of an RFA. Could be wrong, but that's at least the way I read it.