Angular - how to position a context menu in a table row using a 'return' key

Environment: Angular, Bootstrap4. For now this step is chosen to make the table more accessible. In the near future we will make tables visible in a more WCAG way. Please focus on this question.

Each row in a table with dynamic data contains a context menu. See the picture below. Of course this is a simplified version with only 2 options.

Using the context menu the user selects an action. Normally the context menu is activated with a mouse click or right mouse click. The event data is used to position the context menu. The context menu contains in this simple case 2 items: Show and Edit. Works fine for years. I could make the menu more visible, of course.

When the context menu is in the tab order, the user could activate the menu with a 'return'. The problem is that the coordinate of the event is then anywhere on the page.

The context menu code is:

<div tabindex="-1" *ngIf="contextmenu===true">
  <app-contextmenu [x]="contextmenuX" [y]="contextmenuY" [menuitems]="showMenuOptions()"
                   (menuItemSelected)="handleMenuSelection($event)"></app-contextmenu>
</div>

How can a retrieve the coordinates (x,y) from the tab-selected context menu, so being the dots icon or table cell? That position I can use to position the context menu.

Each table rows contains this last table row code:

<td tabindex="0" class="col-1" (click)="onrightClick($event, journalEntry)" (keydown.enter)="onrightClick($event, journalEntry)"
    (contextmenu)="onrightClick($event, journalEntry)">
  <fa-icon [icon]="ellipsisV" size="1x" alt="..." aria-label="..."  [styles]="{'stroke': 'blue', 'color': 'blue'}"></fa-icon>
</td>

When a page contains a context menu, I put this at the bottom of the page:

<div tabindex="-1" *ngIf="contextmenu===true">
  <app-contextmenu [x]="contextmenuX" [y]="contextmenuY" [menuitems]="showMenuOptions()"
                   (menuItemSelected)="handleMenuSelection($event)"></app-contextmenu>
</div>

The code for the context menu is:

<div class="contextmenu" [ngStyle]="{'left.px': x, 'top.px': y}">
  <ul class="list-group">
    <li class="list-group-item" *ngFor="let menuItem of theMenuItems">
      <span (click)="outputSelectedMenuItem( menuItem)">{{ menuItem }}</span>
    </li>
  </ul>
</div>