Hi @André Pinho,
You can customise the cluster icon with css, currently these are just css vars that customize a background.
So you can overide these vars like:
.custom-clustericon{
--cluster-default-image-1:url('data:image/png;base64,....');
--cluster-default-image-2:url('data:image/png;base64,....');
--cluster-default-image-3:url('data:image/png;base64,....');
}
Let me know if this helps you,
Best Regards,
João Ferreira