Token read positions of cursive attachment anchors

[hassanhamid (hassan)]

I want write token read positions of cursive attachment anchors that mean that i want read location of cursive attachment anchors
I want use it with arabic

[FlorianPircher]

See Glyph Property Tokens on page 118, section 8.4.4 Tokens in the Glyphs 3 handbook:

glyphs-3-handbook.pdf