How to execute method after all forEach loop completed using node.js

Question

Hi I am facing one issue. I need to execute one method after all nested forEach completed using node.js. I am explaining my code below.

let jsonArr = _.get(req, ['body', 'test_suite']);
jsonArr.forEach(async ele => {
     let stepsArr = ele.steps;
     let devices = ele.devices;
     let deviceArr = devices.split(',');
     let arr = [];
     deviceArr.forEach(e => {
        arr.push({ 'name': e });
     })
      ele.devices = '';
      ele.devices = arr;
      stepsArr.forEach(async el => {
           if (el.operation === 'PATCH' || el.operation === 'PUT' || el.operation === 'POST') {
                        if (el.attachments && el.attachments[0].content === '') {
                            fileFlag = false;
                            msg = '_id is mandotary for POST/PATCH/PUT operation.';
                        } else {
                            const cid = el.attachments[0].content;
                            const result = await findById(cid, 'useCaseFile');
                            if (result.status === 1 && !_.isEmpty(result.data)) {
                                const contentToBase64 = result.data.fileData;
                                el.attachments[0].content = '';
                                el.attachments[0].content = contentToBase64;
                            }
                     }
             } 
        })
 })

console.log('jsonArr', jsonArr)
let originalJSON = {};
originalJSON['test_suite'] = jsonArr;
originalJSON['schema'] = "hello";
originalJSON['version'] = 10;
await downloadFiles(res, originalJSON, 1);

So here I need after finishing the nested loop execution then the console message should print and also downloadFiles method should invoke. But as per my code before finishing loop execution console.log is executing and also downloadFiles method is invoking as result I am not getting the right result. Here I need after finishing the all nested loop execution the stuffs below console message should execute.