Does the supplication: "O Allah, be a Protector, a Helper, and a Trustee for Muslims" entail a Shariah-related issue, given that Allah is the Lord of all creation?

It is permissible to supplicate with the phrase "Ya Amin" (O Trustworthy One) because it falls under the category of informing about Allah Almighty, and this name carries a valid meaning. The name "Al-Muhaymin" (The Guardian) appeared in the Holy Quran, and it signifies Al-Amin (The Trustworthy One) in some interpretations, as stated by Al-Bayhaqi, Ibn Al-Jawzi, Ibn Atiyah, Al-Zajjaj, and Al-Fayrouzabadi. Furthermore, in the Arabic language, Al-Amin means the Preserver and the Watcher, both of which are among Allah's beautiful names. It is permissible to inform about Allah using names that carry good meanings, provided they are not negated in the Quran and Sunnah and their general category is affirmed therein.