This is a 6 kyu problem: all you need to know is how to iterate on a list, some branching and how to use a dict

there is no need to get katakana alphabet set
if u do the others proply the katakana one should be ok
check the rest code if theres some mistake

Read the description again:

Any character not in the alphabet must be left as is. For example (following from above):

c.encode('CODEWARS'); // returns 'CODEWARS'

It IS a problem with your code, not a kata issue. Use Question label next time.

Read the error message, it clearly points to where the problem is.

print('abc'.index('B'))

That will give you a similar error.

Be an example for your kids: don't post crap.

Didn't you notice the button next kata on top right?

Select python version 3.8 at the top.

An issue is a bug in the kata, not your code not working. Please read this: https://docs.codewars.com/training/troubleshooting/