https://www.epo.org/en/service-support/faq/law-practice/list-professional-representatives-entry/how-can-i-request

How can I request an exemption from the nationality requirement under Article 134(2)(a) EPC pursuant to Article 134(7) EPC for entry on the list of professional representatives?

Such an exemption may be granted if you have lived for a period of at least four years in an EPC contracting state, are employed at a patent law firm or in the patent department of a company and have shown a real intention to stay there on a permanent basis and practise as a European patent attorney. You should supply a letter of motivation and documentary evidence (e.g. certified copies of confirmation of employer, residence permit, proof of rent, date of first entry into the contracting state, etc.). The discretionary decision lies with the Vice-President Directorate-General 5.