Facing issue while Setting up Grafana from HTTP to HTTPS

I have successfully running a grafana instance on my server. It runs on http without a problem. Now I want to switch from http to https . My grafana.ini is shown bellow:

[server]

Protocol (http, https, h2, socket)

protocol = https

The http port to use

http_port = 8080

The public facing domain name used to access grafana from a browser

domain = mydomain.com

Redirect to correct domain if host header does not match domain

Prevents DNS rebinding attacks

enforce_domain = false

The full public facing url you use in browser, used for redirects and emails

If you use reverse proxy and sub path specify full url (with sub path)

root_url = %(protocol)s://%(domain)s:%(http_port)s/

Serve Grafana from subpath specified in root_url setting. By default it is set to false for compatibility reasons.

serve_from_sub_path = false

Log web requests

router_logging = false

the path relative working path

static_root_path = public

enable gzip

enable_gzip = false

https certs & key file

cert_file =“C:\Program Files\GrafanaLabs\grafana\wildcard.cer”
cert_key =“C:\Program Files\GrafanaLabs\grafana\wildcard.key”

I am getting the below error while starting the grafana service

t=2022-02-10T17:04:19+0000 lvl=info msg=“HTTP Server Listen” logger=http.server address=[::]:8080 protocol=https subUrl= socket=
t=2022-02-10T17:04:19+0000 lvl=eror msg=“Stopped HTTPServer” logger=server reason=“tls: found a certificate rather than a key in the PEM for the private key”
t=2022-02-10T17:04:19+0000 lvl=info msg=“Stopped Stream Manager”
t=2022-02-10T17:04:20+0000 lvl=eror msg=“A service failed” logger=server err=“tls: found a certificate rather than a key in the PEM for the private key”
t=2022-02-10T17:04:20+0000 lvl=eror msg=“Server shutdown” logger=server reason=“tls: found a certificate rather than a key in the PEM for the private key”

Can some one help me on this.

Have you generated the .cer and .key files yourself for a self-signed certificate or has some certificate authority supplied the files?

If you generated them yourself let us know exactly how.

If you look at the files does the .key file look like a key file and the .cer file look like a certificate file? e.g. in my case the .key file starts with:
-----BEGIN PRIVATE KEY-----
and the .cer file starts with:
-----BEGIN CERTIFICATE-----

Created file with self- signed certificate only.

But when i Open the Key file and cer file

Both started with -----BEGIN CERTIFICATE-----