You need add a filter url argument. You must first define the table and field you want to filter, then add the filter's value following eq. As a consequence, your final product should look like this:
URL?filter=Table/Accountid eq 123.
Microsoft's material on the subject can be found here. https://docs.microsoft.com/en-us/power-bi/collaborate-share/service-url-filters#query-string-parameter-syntax-for-filtering
The top half of the course has been updated to work for filtering reports in the appor work space. You must provide the page and filter in a similar manner for the embedded link https://docs.microsoft.com/en-us/power-bi/collaborate-share/service-embed-secure to filter the embedded report. As a result, your link will look like this:
https://app.powerbi.com/reportEmbed?blabla&pageName=Page1&$filter=Table/Accountid eq 123