espocrm-base/application/Modules/Crm/Metadata/viewDefs/Prospect.json

{
   "viewMaps":{
      "detail":"Crm:Prospect.Detail"
   },
   "menu":{
      "list":{
         "buttons":[
            {
               "label":"Create Prospect",
               "link":"#prospect/create",
               "style":"primary",
               "acl":"edit"
            }
         ]
      },
      "detail":{
         "buttons":[
            {
               "label":"Convert to Lead",
               "action":"convertToLead",
               "acl":"edit"
            }
         ]
      }
   }
}