Why should you get the CA SDI back? That's only if not have 2 or more employers. On your W2, what box is the SDI in? If it is in box 19 you need to move it to box 14 to get credit for it.
The SDI taxable wage limit is $118,371 per employee for calendar year 2019. The maximum to withhold for each employee is $1,183.71. If one employer took out more you have to get it back from the employer. So enter the max for box 14 on that W2.
Excess CA SDI will be on CA 540 line 74. See 540 Instructions Page 13 line 74
https://www.ftb.ca.gov/forms/2019/2019-540-booklet.pdf
