test.js

        let imageNumber = 1;

        if (this.state.pic1 && this.state.pic1.uri) {
            let obj = {
                uri: this.state.pic1.uri,
                type: this.state.pic1.type,
                name: 'image.jpg',
            };
            formData.append('Pic' + imageNumber, obj);
            imageNumber++;
        }

        if (this.state.pic2 && this.state.pic2.uri) {
            let obj = {
                uri: this.state.pic2.uri,
                type: this.state.pic2.type,
                name: 'image.jpg',
            };
            formData.append('Pic' + imageNumber, obj);
            imageNumber++;
        }

        if (this.state.pic3 && this.state.pic3.uri) {
            let obj = {
                uri: this.state.pic3.uri,
                type: this.state.pic3.type,
                name: 'image.jpg',
            };
            formData.append('Pic' + imageNumber, obj);
        }