SourceTree keeps failing authentication even though the username and password are correct

[Deleted user]

Hi,

SourceTree keeps throwing authentication errors even though my username and password are correct:

remote: Invalid username or password
fatal: Authentication failed for 'https://ec_ho@bitbucket.org/ec_ho/flipnote-theatre.git/'

Pushing to https://ec_ho@bitbucket.org/ec_ho/flipnote-theatre.git
Completed with errors, see above.

[Deleted user]

An update:

I've tried https://stackoverflow.com/questions/45622960/sourcetree-remote-invalid-username-or-password however, I get this error:

http://prntscr.com/l0g3so