I found it from the following sentence.
はてね その先はどうつなぎゃいいんだ。
「つなぎゃ」 is the colloquial pronunciation of 「つなげば」= 「繋げば」
The meaning of the sentence 「はてね その先はどうつなぎゃいいんだ。」 is highly contextual.
「つなぐ」 can mean "to tie", "to fasten", "to connect", "to keep something going", etc.
I would be inclined to think that it would be about keeping a story/explanation going in a logical manner -- something like "How should I keep it flowing from here?" -- but without further context provided, this would be nothing but speculation.
Other examples of colloquial conditional forms:
開{ひら}きゃ、食{た}べりゃ、見{み}りゃ、泳{およ}ぎゃ、行{い}きゃ、いりゃ、ありゃ, etc.