Hi ak1,
Go to dashboard -> Customize -> Site Identity and upload the logo. There must be an logo options.
Then after go to dashboard -> Customize -> wp portfolio theme options -> Header options and select Header Logo Only from the radio button.
Doing this the logo must be appeared if you have not made any code customization in the theme. If you still have an issue then could you please Email Us your temporary username and password with site url. We will look what is the exact issue.
Don’t forget to sent this forum link too.
Thank you!