Convert Number to Ordinal Using Microsoft Flow

Implementation Steps:

1. Open https://flow.microsoft.com

2. Click New Flow

3. Select Manually Trigger Flow

4. Add a Number Parameter

5. Click Add and Add Compose

if(endsWith(string(triggerBody()['number']),'11'),formatNumber(triggerBody()['number'], '#th'),
if(endsWith(string(triggerBody()['number']),'12'),formatNumber(triggerBody()['number'], '#th'),
if(endsWith(string(triggerBody()['number']),'13'),formatNumber(triggerBody()['number'], '#th'),
if(endsWith(string(triggerBody()['number']),'1'),formatNumber(triggerBody()['number'], '#st'),
if(endsWith(string(triggerBody()['number']),'2'),formatNumber(triggerBody()['number'], '#nd'),
if(endsWith(string(triggerBody()['number']),'3'),formatNumber(triggerBody()['number'], '#rd'),
formatNumber(triggerBody()['number'], '#th')))))))

6. Add Respond to the Flow with the OUTPUT 

Sample:

Thanks to @Expiscornovus