New version 4+ is released. Please use official docs

# Row headers

Excel like feature. Shows row number at the left side of the table. If row-headers is true then it's available. false by default.

<revo-grid row-headers="true"/>

Or from the code:

const grid = document.querySelector('revo-grid');
grid.rowHeaders = true;

Alternatively you can use rowHeaders as additional fixed column on the left. rowHeaders accept all params as regular column does (size, cellTemplate etc).

const grid = document.querySelector('revo-grid');
grid.rowHeaders = {
  size: 200
};