Testing Plasma 6 (Beta) on Endeavour OS - is this approach any good?

Edited my pacman.conf:

# The testing repositories are disabled by default. To enable, uncomment the
# repo name header and Include lines. You can add preferred servers immediately
# after the header, and they will be used before the default mirrors.

[kde-unstable]
Include = /etc/pacman.d/mirrorlist

[core-testing]
Include = /etc/pacman.d/mirrorlist

[extra-testing]
Include = /etc/pacman.d/mirrorlist

[endeavouros]
SigLevel = PackageRequired
Include = /etc/pacman.d/endeavouros-mirrorlist

[core]
Include = /etc/pacman.d/mirrorlist

[extra]
Include = /etc/pacman.d/mirrorlist

Running yay now results in:

:: Synchronizing package databases...
 kde-unstable is up to date
 core-testing                                                                                      1236.0   B  5.49 KiB/s 00:00 [-----------------------------------------------------------------------------] 100%
 extra-testing is up to date
 endeavouros is up to date
 core is up to date
 extra is up to date
 multilib is up to date
error: GPGME error: No data
error: failed to synchronize all databases (unexpected error)
 -> error refreshing databases - exit status 1

I found an article [1] that suggests how to resolve this error, but I 'm unsure about the procedure (which is new to me). Any suggestions, ideas?

[1] https://vadosware.io/post/fixing-gpgme-error-on-arch/