nomrally the lower left part of the I-797A H1 approval notice is the I-797C and the lower right part of the I-797A is the I-94. So, there will not be a separate I-797C mailed to you in this case. So, just check the I-797A and detach the lower left and right parts for your personal record. The top part of the I-797A approval notice is for your HR. Anyway, I-797A and the I-94 are enough for you.