How to pronounce YouTube (Toob or Choob)

American "tube" = /tuːb/, think "toob"

Modern British "tube" = /tʃuːb/, think "Choob"

tube
noun
UK
/tʃuːb/ US /tuːb/

https://dictionary.cambridge.org/dictionary/english/tube?q=TUBE

tuna
noun
UK
/ˈtʃuː.nə/ US
/ˈtuː.nə/

https://dictionary.cambridge.org/dictionary/english/tuna

B1 [ C ] plural tuna or tunas
a large fish that lives in warm seas:
shoals of tuna