I have a question about metadata and covers

[Rouge One]

I am confused here I try to get metadata data for a book so I could get a cover to download & it keep saying to use the authors name & title of the book I did that as the person was named & it did not work & then it said to use the last name & the book title & that did not work either does anybody know why this is happening & how to fix it

[DNSB]

Depending on the metadata sources, a lot of them are blocking requests very enthusiastically. If you look at the log file from from the Edit Metadata dialog, what does it show?

I've attached a sample log from a failure trying to get data from Amazon which ends in a HTTP 503 error which basically says Amazon doesn't want to talk to me. The other option that comes up often says "could not defeat CloudFlare protection".

If I wait a couple of minutes and repeat the download metadata request, it might work. If I go away for 10-15 minutes, I get 4-5 successful requests before it errors again.

Spoiler:

calibre, version 8.0.1
ERROR: No matches found: <p>Failed to find any books that match your search. Try making the search <b>less specific</b>. For example, use only the author's last name and a single distinctive word from the title.<p>To see the full log, click "Show details".

Running identify query with parameters: 
{'title': "1635: The Weaver's Code", 'authors': ['Eric Flint', 'Jody Lynn Nye'], 'identifiers': {'isbn': '9781982193669', 'google': 'l26M0AEACAAJ'}, 'timeout': 30} 
Using plugins: Amazon.com (1, 3, 12) 
The log from individual plugins is below 

****************************** Amazon.com (1, 3, 12) ****************************** 
Found 0 results 
Downloading from Amazon.com took 1.6002821922302246 
User-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36
Server: amazon
Failed to make identify query: 'https://www.amazon.com/s/?search-alias=aps&unfiltered=1&sort=relevanceexprank&field-isbn=9781982193669'
Traceback (most recent call last):
  File "d:\calibre\calibre-master\src\calibre\ebooks\metadata\sources\amazon.py", line 1511, in search_amazon
  File "mechanize\_mechanize.py", line 241, in open_novisit
  File "mechanize\_mechanize.py", line 313, in _mech_open
mechanize._response.get_seek_wrapper_class.<locals>.httperror_seek_wrapper: HTTP Error 503: Service Unavailable 

******************************************************************************** 
The identify phase took 1.60 seconds 
The longest time (1.600282) was taken by: Amazon.com 
Merging results from different sources
We have 0 merged results, merging took: 0.00 seconds