When I use font for Arabic or hebrew language, the letters follow one another automatically from right to left. But if I create a font, in this one the letters always come in succession from left to right. Is this a planning to write in the orientation that I choose for my font?
I don’t create RTL fonts, but I think what you need to do is calculate Ranges and Code Pages in Font Properties.
The default orientation is defined by Unicode. You can ask them to include a new script.
Easier is to abuse an existing script like Arabic or Hebrew.
Alternatively there is a special right-to-left override character defined in Unicode ($202E) that instructs the text processor, rasterizer, or software to display characters from right-to-left.