Ii is a dying or dead juniper. Junipers tend to die slowly from the inside out. So by the time they are showing significant browning as your is, they are probably goners.
GC is right. It is not an indoor tree. It needs cold winter dormancy and it hates dry indoor air.
Not relevant to its care, but just as a point of information, it isn't cascade style. Cascade is trained downward so that the tip of the tree is below the bottom of the container and most of the foliage is below the level of the soil. Even a semi- cascade ends up below the soil level. You could only call this a slanting style. https://www.brusselsbonsai.com/stylesofbonsai.cfm
Sorry to be the bearer of bad tidings!