In most jurisdictions you do not need attach a Request for Citation form to your initial eFiling in the case. Most jurisdictions allow you to simply select for service under court services.
However, go here to see the citation request policies for the larger jurisdictions in Texas: http://feedback.filetime.com/knowledgebase/topics/47231-clerk-policies
On the document upload page, Under Court Services, select Issuance of Citation (the language will vary depending on the jurisdiction).
Be sure to indicate how many citations you need.
Additionally, be sure to indicate the number of copies you need - the number of pages of the document(s) to be served times the number of citations needed.
Continue on with your eFiling in the usual manner.