How to generate the private keys that begin with "L" or "K"

[XiaLeon]

https://bitkeys.work/?page=0
I wanted to generate the private keys like above which begin with "L" or "K"
Then my code is like this:

`kg = blocksmith.KeyGenerator()

kg.seed_input('35hK24tcLEWcgNA4JxpvbkNkoAcDGqQPsP') // the parameter is a bitcoin address

key = kg.generate_key()

print("key is: ", key)`

The output is:
key is: 0787aa5c4ab37dea0e87073cbc901d8b27d2e861f833673157878c019484e3bd
It doesn't begin with "L" or "K", can you help please? thanks a lot