QGIS Plugin 'Curve Number Generator' has multiple algorithms to generate the curve number layer for any area of interest using different datasets.
Curve Number Generator Plugin can be downloaded from official QGIS plugin repository (see the demo below) or from https://github.com/ar-siddiqui/curve_number_generator/releases
Siddiqui, Abdul Raheem. 2020. “Curve Number Generator: A QGIS Plugin to Generate Curve Number Layer from Land Use and Soil.” Accessed [Month Year] at https://github.com/ar-siddiqui/curve_number_generator.
If this plugin is useful for you, please consider making a donation of any value to the developer.