Data extraction of Postcodes + full addresses from the web

Dear freelancers, I have a job that I need help with:
I need data extraction from the web, postcodes! I need to complete a list of addresses with postcodes I don't have. And then, with those postcodes, I need to use this website:
https://www.landlordregistrationscotland.gov.uk/search/start?
The postcodes retrieved previously by you, will be the data entry on this website link above, which will give you a list of addresses in that same postcode (pic1) , you will have to pick the correspondent 'premises' address on the list given by me, in order to get the specific residential address from the applicants on that same list given by me.

Resumed: I want all the addresses on the section 'Registration details for this property',
All info needs to be in excel spreadsheet in columns with names, addresses and postcodes, so I can use to do a mail campaign.
I can give you 3-4 postcodes for you to check/ practice and I will verify it, to check if you understood the task.

Example1: 1/2 Leven Terrace, Edinburgh. EH3 9LT.
1/2: Because the '1' is the building number, and the '2' is the floor/flat number.

Example2: "1f2, 48 South Clerk Street, Edinburgh" I checked the address "48 South Clerk Street, Edinburgh".
you then pick '48/1 south clerk street, edinburgh', because it's the 1st floor on the building nr 48.

Thank you.

All the best,
Patricia