Go to the assessment of your choice and click on "Invite candidates" at the top right of your screen:
From this panel, you can copy the invitation link from the assessment (and paste it into an email, job advert, etc.). You can also generate a QR code that you can share with all your candidates.
⚠ Make sure that the link or QR code has been copied: a pop-up appears at the bottom of your screen when this is the case: