DO I HAVE TO GO ON TESTOSTERONE BEFORE HAVING A BREAST REMOVAL FTM TRANSGENDER?

No. It depends on the plastic surgeon you see. They often do want you to establish care with a mental healthcare provider specialized in transgender mental health. Find a good plastic surgeon that has experience with "top" surgery.
No. Testosterone can increase risk of certain health conditions - esp. Heart disease, stroke, diabetes & certain types of cancer. Thus some affirmed males are advised against taking it or choose not to take it. And though it may improve the esthetic outcome of gender-affirming chest surgery in some individuals, surgeons following wpath standards of care (wpath.Org) should not *require* it be taken.
Transgender. Normally the steps are counseling then hormones & surgery is at the end of the line.

Related Questions

How much does it cost average for a breast removal on a transgender female to male and do you need to be on testosterone to get it done?

From 8-20K. Since this is a cash service you will find a broad range of prices offered. Make sure the price you are quoted includes contouring the chest are so it doesn't look like butchery. Taking testosterone will improve and hasten transition and is preferred but is not required. Read more...
"TOP Surgery" ~$6000. A reduction mammoplasty or top surgery done on a female-to-male transgendered person runs about $6000, but the cost varies. You don't have to be on testosterone to have this done, but most people are - as they have already sought counseling and have initiated their hormonal transition. Most people are very relieved to have this done: no more binders - and the ability to finally wear tank tops! Read more...