@itsdustme or anyone else that needs help... I just got this running as follows (m1 mac air)
installed flow via download from github
installed npm:`brew install npm`
ran this in the flow directory (as mentioned above): `npm install`
retrieved api key and DB id from notion.so as required and added them to the flow vars
this was the part that hung me up for a while... you have to specifically share the DB with the api integration you just created. as so: https://developers.notion.com/docs/getting-started#step-2-share-a-database-with-your-integration
Once I did step 5 everything worked :)))))
good luck, and thanks to the creator of this workflow!! @Paulo