"Spides" is a Syfy Deutschland production and it originally aired on Syfy Deutschland from March 5 to April 23, 2020. Syfy Deutschland doesn't provide English captions, that's why there are no English subs.
It also aired on Syfy Portugal from April 1 to May 20, and it's been airing on Syfy España from April 27 to June 15. No English captions in those countries either.
The good news is that the show finally comes to an English-speaking country. It will be on Syfy UK on Tuesdays from June 16 to August 4, 2020. So, English subs may become available then.