In Odoo16 I created a new property in CRM Lead and named it "Plate No."

First, I didn't find a field named "Plate No." in the list of Odoo Fields in the Import screen!! So, I found Odoo Field "Properties", I tried to use it, but I got the error 'NoneType' object is not callable

Second, I filled the "Plate No." field in one of the leads and exported the list of leads to understand how to fill it. The result was like this for that lead was: 

[{'name': '3405444982add8c0', 'type': 'char', 'string': 'Plate No.', 'default': '', 'value': '06 BVZ 477'}]

while the result for the blank properties was this:
[{'name': '3405444982add8c0', 'type': 'char', 'string': 'Plate No.', 'default': '', 'value': False}]

In excel, I replaced the text "False" with the "Plate No." using this formula "=SUBSTITUTE(D3,"False",CONCAT("'",E3,"'")) where D3 holds the exported value of a blank property field, and E3 holds the "Plate No." value that I want to upload to Odoo, so that all False value has been substituted with the Plate No. encapsulated with single quote mark.

Unfortunately, I still get the same error again 'NoneType' object is not callable

I need a solution, please!!!!