Here it is
HTML Code
<iframe id="sq-card-number" name="sq-card-number" class="sq-input" frameborder="0" width="100%" scrolling="no" height="18" src="https://pci-connect.squareup.com/v2/iframe?type=cardNumber&app_id=sandbox-sq0idp-tVvPe-svMrqgtzNNRvmStg" allowpaymentrequest="true"></iframe>
Below Thing is Script,And Get fails for Input Text Keyword
* TestCases *
Select Frame xpath=//iframe[contains(@id,'sq-card-number')]
Input Text id=sq-card-number Iframe
You do not differ two different element IDs - you need to select the iframe content first (Select Frame) and then you have to wait for your textbox to appear within the iframe - and wait for this. Unfortunately this is not stated above so: find your text input ID and make sure you replace it in the code example below.
Wait Until Page Contains id=sq-card-number
Select Frame id=sq-card-number
Wait Until Page Contains Element id=myTextFieldElement
Wait Until Element Is Visible id=myTextFieldElement
Input Text id=myTextFieldElement Iframe