You should ask its inventor, Prof. Satoshi Arai, Research Institute for Science and Engineering, Waseda University, Tokyo, Japan if he can supply it to you.
Dear Mohamed Ahmed Nasr El-deen, attached is the Supplementary Information of the original 2015 paper by Satoshi Arai et al. The synthesis of the Mito Thermo Yellow (MTY) dye is described in references 2-4. As suggested by Adam B Shapiro, it might also be worth a try asking Prof. Arai for a sample.
Thank you very much Dr. @Frank T. Edelmann. I contacted Dr. Arai and he thankfully answered me. Also, thank you for recommending the references for its synthesis.