Assuming he already has residency in an EU state then he shouldn't need one? At least for the next 3 months.
If it's same as UK you can get residency after 2 years. That entitles you to then work in any EU state.He's only played for Lazio since 2016 and doesn't have dual nationality at all (with no senior international caps), pretty sure that'll bar him from joining.
Solanke not going to palace now. Would rather have Abraham though