Vultr provides plenty documents, there are more than 1,000 articles under 47 topics, each has an amount range from a dozen to hundreds (with overlapping). If you want to deploy some service or debug some problems, it's convenient and reliable to refer to the official documentation.
In order to facilitate the retrieval of the required documents, I spent some time to reorganize them into some subjects according to the topic-subtopic related, and append the excerpt with the title, I hope you find this work helpful.
Vultr Apps / 18 docs in this article.
✔ How to Fix Magento's Readiness Check
The readiness check that is done before upgrading or installing extensions is caused by two separate issues. One is that the cron tasks are either not setup or are in the wrong place. The second is that the PHP-FPM memory limit needs to be set very high or else Magento becomes unstable and will not print out detailed error messages.