The Hasbey Dar'ul Huffazı. It seems this is not a grave but a small medrese.

From Google-translated Konya site: Haji Hasbey son Mehmet Bey (1421) "Hafýzlar House" built this. Brick body resting on a square plan and is covered on three sides over the chipped stone. west façade where the entrance door is decorated with inlaid marble. The body of the dome is passed on to the classic triangle angle. two sides of the triangle are decorated with green tiles. There is also a nice niche in ornate tiles.

From another site: This dome belongs to the Hasbey Medresesi (miş), which stands in an old quarter of the city, stuck in narrow streets, quietly lonely. It was built in 1421 by Karamanoğlu Mehmet Bey. Karamanoğlu is one of the smallest but most beautiful works of the period. Famous for its stone workmanship on its ceiling and tile decorations on its dome.