Go to Docker Settings - the Network tab.
Copy the daemon’s IP address from there (usually 10.0.75.0).
Now go to the Shared Drives tab and click Reset credentials.
Check the Shared checkbox for the drive you want and then Apply. In the dialog that appears, enter as username: the IP address of the daemon, backslash, your Windows username.
Assuming you have the default IP for the daemon, it should look like this:
10.0.75.0\yourwindowsusername
In the password field enter your Windows password.
Apply.
Happy mounting!