You can manually enter the data that a 1099 needs. Do you have your 1099-R from 2017? Use that to fill out the payer info, type of distribution, etc if you are certain that nothing changed from 2017 other than the pension amount. Also, this is assuming that you do not have taxes withheld from your pension. If you do have taxes withheld, you need that amount in order to file. Good luck!