Most common aquarium plant fertilisers are invert and shrimp safe. The only time you need to be careful is when you are using DIY and dry fert mixes. All main brands are fully shrimp safe. Please stick to the advertised dosing instructions.

But it lists copper as ingredient!

Copper contained in aquarium fertilisers are in chelated form and thus non-poisonous for invertebrates and shrimp. This does not apply to DIY ferts and cannot be guaranteed to dry ferts.