Which regional rules of lent fasting or holy days of obligation should a Catholic follow?

If I'm Catholic Argentinian by birth and citizenship and reside in Argentina, then the only thing to check is if I'm Eastern Catholic or Roman Catholic. If I'm - Roman Catholic, - French in nationality and citizenship by birth, - but I recently renounced my French citizenship temporarily - to apply to some other citizenship say of Country X - and have yet to reapply for French citizenship because I don't yet have time - but I intend to reapply for French citizenship - and I reside in Germany, then 1. Which set of holy days of obligation will I follow? (France, Germany, Country X, a certain intersection, a certain union) 2. Which lent fasting rules will I follow? (France, Germany, Country X, a certain intersection, a certain union) 3. How do the answers above change if I reacquire my French citizenship? Of course **I'm not asking specifically** about France, Germany and Roman Catholicism (This question extends to Eastern Catholicism and whatever is full communion with Roman Catholicism). **I'm asking in general**: - Which diocese/region/country/whatever do Catholics (I'm asking for roman catholicism, but you can answer eastern or other full communion's if you want) fall under for purposes of holy days of obligation or lent, do when they have dual or renounced citizenships or when they reside in a country that is not of their citizenship? --- Related: https://christianity.stackexchange.com/questions/75713/are-filipino-roman-catholics-required-to-not-have-meat-on-all-fridays-of-lent https://christianity.stackexchange.com/questions/79822/google-calendar-for-catholic-holdiays-holy-days-of-obligation