If you are running multiple times a day without any GPS watch or running app and do not have a valid public GPS activity link, then you need to just add the distances and times of each run and submit that data manually as a single entry. Of course, as per rules, the maximum distance you can submit this way will be limited to 10 km.
If you use Strava for your runs (or your daily run data is available in Strava via an export from your regular running app or watch), and you have connected your 100 Days of Running account with your Strava account, then our daily Strava run data import process will import your data for multiple runs into your 100 Days of Running account within 24 hours of the run.
If your run data is on another app (not Strava), then you need to follow the below process to make sure it is imported correctly into your 100 Days of Running account. Basically, you will be required to create a Strava account and transfer your run data from your existing running app account to your Strava account (which should be connected to your 100 Days of Running account).
Read this article to understand how to submit data for multiple runs in a day in more detail and the process to do that.