Google Maps url how to define circular marker?

问题:

I want to open the default maps app but instead of the default marker i want a circular marker.

this is what i have...

case Device.Android:
    if (!string.IsNullOrEmpty(_imovel.Endereco.Freguesia))
    {
        uri = new Uri("https://www.google.com/maps/search/?api=1&query=" + _imovel.Endereco.Freguesia);
    }
    else if (!string.IsNullOrEmpty(_imovel.Endereco.Concelho)){
        uri = new Uri("https://www.google.com/maps/search/?api=1&query=" + _imovel.Endereco.Concelho);
    }
    Device.OpenUri(uri);
break;

and this is what i want

Any hints?