If you have a set number of destinations, it might be better to have the user choose one from a simple list or data viewer instead of typing it in. Because if they type “singopore” or “netherlinds” your app isn’t going to recognize that as a valid destination. Using a component designed for listing information allows you to use the green value blocks associated with that component to easily search for the user’s input.
The way you’re looping through data source values is a common way people try to look up values but it’s not the most efficient:
Instead, use a method I describe here: Thunkable and returns a corresponding value from my sheet - #2 by tatiang
You should also be aware that stored variables will slow down Thunkable. It’s better to use app variables inside of loops (or generally any time that you aren’t actually setting the value of a stored variable). So you can assign a stored variable to an app variable and then use the app variable throughout your code.