Can I import data from Quicken?

I agree this is the practical assessment for many people however the answer is actually to a different question though “Is it cost effective to import data from an old accounting system?”

Technically is can readily be do, see

I suggest you message @Dimitris_Kontodimos the person who started that thread if you want it done but don’t have the technical expertise yourself (see How I can create mass payments for sales and purchase invoices - #15 by Dimitris_Kontodimos)