store.js

   async addMediaToGallery({ commit }, { gallery, file }) {
     const formData = new FormData()
     formData.append('file', file)
  
     const options = {
       headers: { 'Content-Type': 'multipart/form-data' }
     }
     const response = await this.$axios.$post(
       `/api/1.0/gallery/${gallery.id}/add-media/`,
       formData,
      options
    )
 
    commit(SET_GALLERY, response)
  }