Mixed content error after activating Autoptimize

Hi,

I have just activated and configured Autoptimize according to your documentation.

After activating the plugin, I get Mixed content warnings specifically about the Cluster Marker icons:

”
Mixed Content: The page at ‘https://inforoses.com/mapa/’ was loaded over HTTPS, but requested an insecure image ‘http://inforoses.com/wp-content/plugins/geodir_marker_cluster/images/m1.png’. This content should also be served over HTTPS.
”

I have tried with Better Search Replace plugin but it does not seem to find these assets in the tables of its settings page.

Since my technical knowledge is very limited, I would appreciate very much any advice, suggestion or recommendation about how to replace the “http” by “https” specifically for the Marker Cluster icons.

I look forward to your reply.

Thank you very much once again for your help.

Best regards.