Anyone can explain me what should i do to capture QUIC/GQUIC packets?
Capture, or have Wireshark dissect?
Wireshark can capture any type of packet on, for example, Ethernet or 802.11. It may, however, either not be able to recognize and dissect some packet types, or may not recognize and dissect them by default.
Wireshark 3.0.x includes dissectors for both QUIC and GQUIC.
The GQUIC dissector attempts to guess whether UDP traffic is GQUIC or not; it doesn't necessarily do so successfully. No changes have been made to it in Wireshark 3.0.x since January 2019.
The QUIC dissector attempts to guess whether UDP traffic is QUIC or not; it doesn't necessarily do so successfully. You can also use Wireshark's "Decode As..." to specify that traffic to or from a particular UDP port be dissected as QUIC. No changes have been made to it in Wireshark 3.0.x since May 2019.