help in creating of PO

hello, i have to create a new PO using transaction ME21N. and i have a requirement to tick the boxes under the Invoice tab under Item Details:

- Inv. receipt

- GR based IV

- ERS

but upon creating the PO, the Invoice tab is already disabled, and I have to tick the checkbox for GR based IV. is there a way for me to edit the tab?

Thanks much.