We analyze a supply chain consisting of a capital-constrained supplier and a platform functioning as a marketplace, where the supplier sells products to consumers via the platform, which charges a commission fee for each item sold. Operating in a market characterized by price-sensitive stochastic demand, the supplier must make simultaneous decisions regarding pricing and production quantity before a selling period. The supplier has three financing options for production: bank financing, platform-guaranteed bank financing, and direct platform financing. Using a Stackelberg game approach, we model these interactions and derive key managerial insights. Our findings reveal that financing choices and commission fees significantly impact the supplier’s pricing and production decisions, as well as the platform’s financing preferences. Generally, while the platform favors direct financing, the supplier prefers guaranteed financing under certain conditions.