How we can create client certificate to install it on Mendix side? and also if app is deployed on sandbox environment, does certificate is required?

My app is calling Rest API (HTTPS) which is throwing error shown in below snapshot. When I am running locally it is giving me error and also I want to deploy it on Mendix Sandbox environment so, It is require their as well?  
1 answers

What you need is not a client certificate, but a certificate authority, see documentation here. Typically, the person who is in control of the REST API, or the server it is hosted on, can supply you with the correct certificate.


From the documentation on the sandbox environments here, it seems that you will not be able to configure this on a sandbox, so either you need to upgrade to a paid tier, or the team controlling REST API needs to add a certificate from a recognized certificate authority.