An alternative to Zoho which is free and potentially you can run on your existing servers is nubuilder
This is how ChatGPT explains nuBuilder Forte... "nuBuilder Forte is an open-source web application that allows users to create and manage databases and applications without extensive coding knowledge. It is often used by individuals or small businesses who require custom database solutions for
www.nubuilder.com
For people who already have the following
a) cloud provider offering access to cpanel that has file manager
b) cloud provider offering similar access to file manager
c) cloud provider offering access to phpmyadmin
e) cloud provider offering additional subdomains
You can be up and running with a development environment in about 1/2 an hour probably for free
I would definitely recommend people taking a look
And here's a link to my personal instructions on how to get the development environment up and running