The ꟃ shows up in Symbola for me.
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I interpreted the horizontal line as showing frication. There are most likely far too many fricatives in my interpretation, but I had no idea what to do with the variants of <h w y> so I put them anywhere. I thing the vowels are probably more correct than the consonants.
/p b t d k g q ʔ/ <p b t d k g q ʔ>
/ɸ β f v θ ð s z ʃ ʒ ɕ ʑ ʂ ʐ x ɣ xʷ ɣʷ χ ʁ ħ ʕ h ɦ/ <ꝑ ƀ f v ŧ đ s z š ž ꞩ ƶ ṡ ẏ ꝁ ǥ ꟃ ẇ ꝗ ɣ ḥ ḩ h ḫ>
/ts dz tʃ dʒ tɕ dʑ/ <c j č ǰ ȼ ý>
/ʋ l ʎ ɫ r rʲ ɻ j w ɥ/ <ʋ l ľ ł r ř ṟ y w ẃ
/m n ɲ ŋ/ <m n ň ŋ>
/i ʉ u e ɵ o ɛ ɔ a/ <i ư u ē ơ ō e o a>
Accute accent represents stress.