Custom Text Messaging sounds for each contact in my phone

[Members_FjJWdjL]

I was able to copy my downloaded text message sounds to my phone and copy them to the notifications file so I can customize my text message sounds, however, I cannot figure out how to customize the sounds for each of my contacts. Help. 

[NoneYa916]

Which app are you using to send text messages? Samsung messages? or Google messages? Or something else?