Migration of database v3-v4

I am trying to migrate strapi v3-v4. My v3 database is in mongoDB and I am trying to write scripts to transfer data in already prepared JSON structure. I am facing issues in migrating the images. Using Axios I am able to fetch data from mongoDB and I am able to design data in same object format but when I am assigning that value to v4 strapi pictures, I am getting null value. V3 was hosted on cloudinary and now I am running it on local host.

You have a migration script

if that does not work then your best option is to recreate all content-types how they where in v3 in v4 and using the v3 api to request all data and then posting it to the v4 database

I am using API request scripts every thing is parsing except scripts