Hello!
Please give it some time for the workout to show up. If you find that after a couple hours it still doesn't show up, you can always "repeat" the workout and fast forward to the end and try sending the data again. MyFitnessPal has been having some issues with users logging in, and so that means that if the c25k app can't log into MFP, then no data is sent.
Another thing to try is to log out of your MFP app, and log back in. That would hopefully reset the MFP app, which then would give c25k app permission to send data.
Thanks! As always, you can send an email to contactus@zenlabsllc.com for more support and help.