I'm filling out my application to be a freelancer at UpWork, and I see no field to add my portfolio! When I tried to add my website to my "overview," I received the message, "External links are not allowed in your overview. You can add a link to portfolio websites in the Portfolio section of your profile." But there is no "Portfolio" section in the application. Please help! Thanks.
You don't need this.
Clients can click on your name and see the portfolio on your Upwork profile page.
But when I look at your profile page, I don't see any portfolio at all. That's a problem.
I strongly urge you to do what successful Upwork freelances do, which is to create a portfolio.
Having said that, there are no restrictions on referring clients to EXTERNAL links or portfolios when you write cover letters/proposals. You can simply provide external links however you want. You don't need a special "portfolio" field, and Upwork will not be creating a special "portfolio" field.
I would like to clarify that once your registration has been approved, you should be able to add more information to your profile, such as your skills, education, and your porfolio items.