angular asynchronous request from multiple methods

From ngOnchanges I called the method _generateLocationFormForApproval and it has an output which is this.absoluteUri. After calling _generateLocationFormForApproval the next call is _pageEventDealsForApprovalList. Now I want to access the result from _generateLocationFormForApproval whic is this.absoluteUri inside _pageEventDealsForApprovalList after its result but it is giving me undefined although this.absoluteUri has a value.

Any idea ? with the asynchronous call ? Thansk.

#code

  ngOnChanges(changes: SimpleChanges): void {
      if(this.dealId) {
        this._generateLocationFormForApproval();
        this._pageEventDealsForApprovalList();
      }
    }
    
    
    
    private  _generateLocationFormForApproval() {
      this.dealService.generateLocationSubmission(this.dealId)
      .subscribe({
        next: (res) => {
          if (res.isSuccess) {
            this.absoluteUri = res.data.absoluteUri;
          }
        },
        error: err => this.notificationService.showError(err),
        complete: noop,
      });
    }
    
private _pageEventDealsForApprovalList() {
  console.log("1")
  console.log("this.absoluteUrithis.absoluteUri" , this.absoluteUri)
  this.searchInput = '';
  const status = [DEAL.STATUS.FORAPPROVAL, DEAL.STATUS.APPROVED]
  this.dealType = [];
  this.isLoading = true;
  this.dealService
    .getAllDeals(
      status,
      this.accountId,
      this.transaction.id,
      this.table.pageIndex + 1,
      this.table.pageSize,
      this.searchInput,
      this.table.sortParams,
      this.table.sortDirs,
      this.dealType
    )
    .pipe(finalize(() => (this.isLoading = false)))
    .subscribe((res) => {
        if(res) {
          console.log("this.uri" , this.absoluteUri)
        }
    }, (err) => this.notificationService.showError(err)
  );
}