HTC one sv recovry *** LOCKED ***

guys i have htc one sv stuck on logo how to flash it?
i try to read how to flash but most of zem says it recovery have to be
*** UNLOCKED ***
BUT!!! my phone is locked

some times it stuck on logo and it says for development only….:confused::confused::confused::confused:
so weird for me pleas help me and how to flash htc phones? toooooo