Something you might do is use a code block and convert the first letter of each word comprising the search term to uppercase, to match what is in your Airtable.
Structurally, a variable with the city name is coming out of the capture block, and it is all lowercase. For example, “london.” A city could also be multiple words, such as “new york,” and in this case there might be a failure if it is “New York” in your Airtable.
This would convert your search terms to “London” and “New York.”
Once the variable is converted, it can be used as a search term in a “filter by formula” URL to find the row with the associated data via your API call to your Airtable.
Another situation is that you might need to do encoding for the space between two words or in case there are special characters, to help make your search term more URL-friendly. This tutorial might help, if you scan through it there should be some tips on how to go about this.