https://www.club-3d.com/shop/cac-1088-1223 (https://geizhals.eu/club-3d-aktiver-adapter-cac-1088-a331004...)

https://www.club-3d.com/shop/cac-1087-1128 (3m cable version)

DP 1.4 → HDMI 2.1. Apparently they're no longer being manufactured (?? - not sure that's correct), so get one while it's still possible...

[Ed.: accidentally linked another adapter that is the other direction. Added 3m & direct manufacturer links.]