Combining Multiple Webhooks into a single CSV

I’ve setup a Sendingblue ‘new event’ module, which is in essence a webhook which posts everytime there is a new ‘event’. From there, I convert it in to a CSV, then upload the CSV to a server.

However, what I want is to get a daily digest CSV, combining all of the webhook data from the whole day as a single CSV.
I thought that adjusting the Schedule setting on the Sendinblue module to ‘once a day’ would then process any and combine them. However all that does is process 1 webhook ever 24 hours…

Any ideas?