Help creating a macro for invoice numbers

[Thriftlife]

Hey needing a way for my company to use the invoice we have created and create a bunch of copies of it and give it its own unique invoice number.
The cell the invoice number will be in is I4
i would like it to save each copy as the same name as the invoice number. As an ex invoice 123 will be saved as 123.xlsx
Also like to have it auto save all the files so i dont have to go and save and change them one at a time.
We usually make 1300 or more copies of invoices that employees fill out, so trying to make it easier on us
,Thanks

 

[Fluff]

Duplicate Need a way to create invoice numbers automatically

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