Duplicate multiple rows

What is the best way to copy rows (about 20-30 rows with 2 level hierarchy, 10 columns).
For now I am using Integromat via webbooks to search and add and it works fine just the delay of synching back to glide… (inserting dummy speeds it up)
My use case is copying a template of a weekly workout program.
Was wondering if anyone found a better solution since I checked last?

I know that @yinon_raviv had a very similar scenario. For his use case, I helped him out with some apps script to add the rows. I doubt that the apps script would be any faster than Integromat, as the data still needs to sync back to Glide. Maybe he has since found a better way to do it…

No I didn’t find a better solution but the 2nd script you did which add all rows at one bulk is working great and it takes about 10-15 sec to all of the to appear in glide after synch