Is there any mention in the Quran or Hadith that indicates repeating certain supplications a specific number of times or at a particular time to gain greater benefit, or is it permissible to supplicate any amount at any time?

Remembrances (dhikr) are divided into restricted and unrestricted. The restricted are those that are bound by a specific time or number, and a Muslim must adhere to them exactly as they were transmitted. As for the unrestricted, it is permissible to recite them at any time and in any number without specifying, otherwise one would fall into innovation (bid‘ah). The supplication for repaying debt: "O Allah, I seek refuge in You from anxiety and sorrow, from inability and laziness, from cowardice and miserliness, from the burden of debt and from being overpowered by men," is an authentic and confirmed Prophetic supplication, and it is recommended to recite it frequently without restricting it to a specific number or time. Likewise, the supplication: "O Allah, suffice me with Your lawful against Your unlawful, and enrich me by Your favor beyond anyone else," has a good chain of transmission, and it is permissible to supplicate with it at any time and in any number.