Check with your employer to confirm whether or not they have included the option to open a 529 Account in your benefits package with Betterment.
If your employer does not offer 529 benefits, you can still enroll in the 529 plan of your choice directly on the plan website. Then, you can connect your 529 account to Betterment. This will allow you to view your 529 within Betterment.
Alternatively, if you already have a 529 Account, you may connect this account to your Betterment account by logging into Betterment on a web browser, and navigate to Settings > Connected Accounts.
Please note that connecting your account via Plaid may limit employer-sponsored benefits, such as making payroll contributions or receiving a match.