If your invitation has expired, there are a couple of things you can do.
First, if you know who has sent your invitation (coach, physical therapist, staff member) you can simply ask them to resend your invitation. Instructions on how to do that can be found here.
If your account was set up by a Sparta Science Customer Success Manager (CSM) and you are receiving this message, please reach out to your CSM and they will gladly resend your invitation. Alternatively, you can email firstname.lastname@example.org and a team member will be in touch.