Ask HN: How to adopt writing culture in my startup?

Hello HN, I am the CTO at a telemedicine startup and we have been building a great platform and operation model, but almost all the knowledge is in our heads so we usually need someone to explain how something work to every new employee.

We have tried multiple tools for knowledge base but the adoption inside the company is very poor.

Do you have any advice on how to promote knowledge sharing and documentation via written tools?