The HTTP layer, called HTTP/3, does HTTP-style transports, including HTTP header compression using QPACK - which is similar to the HTTP/2 compression named HPACK.
The HPACK algorithm depends on an ordered delivery of streams so it was not possible to reuse it for HTTP/3 without modifications since QUIC offers streams that can be delivered out of order. QPACK can be seen as the QUIC-adapted version of HPACK.