Is the word paguei the same in Brazilian and European Portuguese?

Yes

The word "paguei" is identical in both Brazilian and European Portuguese regarding its spelling, grammar (it is the first-person singular, preterite indicative of the verb pagar), and meaning. The only difference lies in pronunciation. In Brazil, the vowels are generally more open and the diphthong "ei" is articulated clearly and rhythmically. In Portugal, the pronunciation is more "closed" and stress-timed; the unstressed vowels are often reduced or shortened, making the word sound more clipped or compressed.

Brazilian Portuguese Examples

1. Eu paguei o almoço. (I paid for lunch.)
2. Paguei o boleto hoje de manhã. (I paid the bank slip this morning.)
3. Paguei tudo pelo Pix. (I paid everything via Pix.)
4. Paguei a conta no cartão. (I paid the bill with card.)
5. Paguei a minha parte. (I paid my share.)

European Portuguese Examples

1. Eu paguei o almoço. (I paid for lunch.)
2. Paguei a fatura hoje de manhã. (I paid the invoice this morning.)
3. Paguei tudo com o MB Way. (I paid everything via MB Way.)
4. Paguei a conta com cartão. (I paid the bill with card.)
5. Paguei a minha parte. (I paid my share.)