wrong key signature for tenor saxophone

I don't understand this. These look like the correct key signatures for tenor sax. Or, do you mean that it should appear in concert?

This is correct. Tenor saxophone is a transposing instrument, sounding major ninth lower than written and thus requiring two more sharps in the key signature. If you prefer to write in concert (sounding) pitch, press the Concert Pitch button. But be sure to turn it off before printing the music or you will be very disappointed with how it sounds when a musician tries playing the untransposed part!

See https://musescore.org/en/node/75466#comment-346086 if you're not familiar with the concept of a transposing instrument.