No, you cannot add a TPM, but the CPU in these should, depending on where the system was originally sold, support intel PTT, which is TPM built into the processor. To enable PTT, the system must be configured for full UEFI support - no legacy mode enabled, meaning the drive will need to be partitioned as GPT -- not MBR.  
 my laptop is 2019  inspiron 15 5570.  can i get tpm2.0 into my laptop
tpm 2.0