I do project and I use MySql. I like HeidiSql interface and generally this, so I would like to connect to my local database. But I really feel and maybe I am dumb because whatever host name I put I have errors. Anyway when I type @@hostname in cmd I see my windows authentication username, which also does not work for me.
Mysql Workbench work properly...
Default authentication plugin for MySQL has been changed in recent versions. Not all client programs out there have added support for it yet. You can check if HeidiSQL has released any latest version which adds this support. If it is not, then only solution is to change default authentication plugin on MySQL server and recreate the user. It is described in below links.
https://www.heidisql.com/forum.php?t=24939
https://github.com/HeidiSQL/HeidiSQL/issues/163