Why are there no mushrooms growing from my kit?

Well-developed Mycelium is vital for fruit production so the answer to this question will depend on whether there is visible mycelium in the substrate:

Yes, there is visible white mycelium covering the substrate inside the bag:

If visible white Mycelium covers the substrate inside the bag after 30 days of transitioning the kit from incubation to fruiting, and still no mushrooms have appeared, the issue may be high ambient temperature. In such cases, we recommend refrigerating the substrate bag for 24 hours to induce a cold shock which can trigger fruiting. Ensure the fruiting spot aligns with the correct temperature range for your specific mushroom variety.

No, I can't see mycelium covering the substrate inside the growing bag:

If no mycelium is visible in the growing bag, it signals potential contamination during an earlier stage, hindering the expected development and growth of the kit. This is likely to have resulted from ineffective pasteurisation or contamination during mixing, possibly from hands.