Endoscopy for reflux symptoms. For this?

I have persistent sore pain in the lower throat right side for the last 8 weeks. Went to ENT and did a nasal scope. It was normal. Thyroid ultrasound is normal. GP told me to see the gastro doctor. I have constant pain in this sore spot in the lower throat right side. Persistent sore throat and constantly painful. Along with this , I have reflux symptoms like hoarseness in the voice, throat clearing all the time, feeling of something like ball/lump in the throat, lump feel is worse after eating food. Able to swallow food. Gastro doctor gave medicines but still recommended endoscopy. He is telling me to do endoscopy to check for throat symptoms. Throat right side feels blocked and lump like feel. Left side is empty. But right side feels blocked and full. Constantly. Is this reflux ? Does reflux cause pain in one spot? Is endoscopy necessary for this?