Please help install the Let's Encrypt certificate

aikons.kz resolves as:
104.239.213.7
198.105.244.11
OR
Non-existent domain

depending on which global DNS service used.
This indicates DNS access or propagation issues.
You must ensure DNS is functional and up-to-date before proceeding.

Is probably misstated and really means:
Too many requests for this domain ("aikons.kz") - like too many pending authorizations and such.
You can review actual domain registrations at: crt.sh | %aikons.kz
Which appear normal.