Headers Authoritation doesn't send to backend api

[AhmedHossamFCI]

Hi all,
when the library execute the API, the headers doesn't works. Authorization is null.
I'm using Angular 9

this is config I used,

this.afuConfig = { multiple: this.multiple, formatsAllowed: this.fileTypeExts, maxSize: this.maxSize, uploadAPI: { url: environment.uploadApi, method: "POST", headers: { "Content-Type": "multipart/form-data", 'Authorization':Bearer ${this.accessToken} }, withCredentials: true, }, theme: this.theme, fileNameIndex: this.allowFileNameIndex, hideProgressBar: this.hideProgressBar, hideResetBtn: this.hideResetBtn, hideSelectBtn: this.hideSelectBtn, replaceTexts: { sizeLimit: this.translate('SizeLimit'), selectFileBtn: this.translate('SelectAttachment'), resetBtn: this.translate('Reset'), uploadBtn: this.translate('UploadAttachment'), dragNDropBox: this.translate('DragAttachmentAndDropHere'), attachPinBtn: this.translate('SelectAttachment'), afterUploadMsg_success: this.translate('SuccessfullyUploaded'), afterUploadMsg_error: this.translate('UploadFailed') } };