Who probably invented the Dogri script?

Raja Shakti Karan (more than 5000 years ago), the mighty ruler of Jammu possessed the kind disposition and was adorned with qualities of learning. He therefore introduced many laws in accordance with the customs of the Shastras and devoted much time in the performance of religious rites. For this reason he came to be known as ‘Raja Shastri’. It was the Raja Shakti Karan who innovated the Dogra (now Dogri) script for first time which came to be known as “Ganmat”. Ganmat was descended from Brahmi script and was an extended form of Sharda script.