My frontend application uses https, so does apmserver need to use the same ca certificate?

If apmserver enables https, then my other backend applications do not use https. Does it affect them?

I use the certificate generated by "elasticsearch-certutil http", can apmserver use it to enable https?

apm-server.ssl.enabled: true
apm-server.ssl.key: "/etc/pki/instance.key"
apm-server.ssl.certificate: "/etc/pki/instance.crt"