Thank you, this was the problem

but I still can't update the tree view, I've tried to set attribute create=true using position="attributes" and even by replacing the whole tree with a copy having create=true and nothing changed

i still can't find the "Import" and "Create" buttons

can you plz help me with that

Hi,
The case sensitivity of the 'true' value may be the issue. ,Give the expression as:
< xpath expr="//tree" position="attributes">
< attribute name="create">true</attribute>
< /xpath>
And the import option you can find under favorites menu in odoo 14