wp-admin/admin-ajax.php' POST requests

my website keeps crashing and the reason given by my hosting company is below. Can you advise if there is anyway for me to reduce the admin post requests.

The server as well as the website continue to be experiencing issues. The problems seem to be originating from the combination of high traffic and that traffic generating a large amount of '/wp-admin/admin-ajax.php' POST requests. I can see most of the URLs are of the type https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flgvtheory.co.uk%2Ftopic%2Fcase-study-89&data=02%7C01%7C%7Cdd150570b4004603934608d55c698943%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636516530691770901&sdata=sD2zWk6%2BjzF0LP2NdPhHRD9VkrZhfNMzfAnk0b7fiYA%3D&reserved=0 and they are the ones generating the queries and they in turn are generating the load.

The load is then exhausting the RAM which in turn kills the MariaDB service as its the one with the most usage. You can upgrade the RAM but I would heavily recommend asking your developer to reduce the admin-ajax calls as they appear to be the main issue. All the server's traffic is currently genuine from what we can tell