Thank you for your help, mglae, unfortunate I couldn't get your plugin to work
Congratulation, you found a Kodi bug . Installation from ZIP is failing when no repository is available.
To the RTL8821C issue:
Code
Feb 14 00:24:54.424500 LibreELEC kernel: #PF: error_code(0x0000) - not-present page
Feb 14 00:24:54.424569 LibreELEC kernel: PGD 110000067 P4D 110000067 PUD 110224067 PMD 0 Feb 14 00:24:54.424585 LibreELEC kernel: Oops: 0000 [#1] SMP NOPT
Feb 14 00:24:54.424601 LibreELEC kernel: CPU: 2 PID: 460 Comm: systemd-udevd Tainted: P O 6.1.11 #1
Feb 14 00:24:54.424613 LibreELEC kernel: Hardware name: HP HP Desktop M01-F0xxx/8643, BIOS F.31 03/29/2021
Feb 14 00:24:54.424623 LibreELEC kernel: RIP: 0010:rtw_pci_read32+0x16/0x20 [rtw88_pci]
Feb 14 00:24:54.424651 LibreELEC kernel: Code: 48 03 b7 a0 7a 00 00 48 89 e5 66 8b 06 5d e9 05 77 89 ee 90 f3 0f 1e fa 0f 1f 44 00 00 55 89 f6 48 03 b7 a0 7a 00 00 48 89 e5 <8b> 06 5d e9 e6 76 89 ee 66 90 f3 0f 1e fa 0f 1f 44 00 00 55 89 f6
[...]
Page fault when accessing the card, likely there is still something missing.