The discovery of the phenomena of neutrino oscillations was the first firm experimental evidence of physics beyond the Standard Model (SM). To explain the neutrino masses and mixing, it requires an extension of the SM, called as beyond SM (BSM). The models describing BSM physics often comes with some additional unknown couplings of neutrinos termed as Non Standard Interactions (NSIs). The idea of NSI was initially proposed by Wolfenstein, where he explored how non standard of neutrinos with a vector field can give rise to matter effect in neutrino oscillations. Apart from that there is also an interesting possibility of neutrinos coupling with a scalar field, called scalar NSI. Instead of appearing as a matter potential, scalar NSI appears as a medium dependent correction to the neutrino masses, which may offer unique phenomenology in neutrino oscillations.In this work, we have performed a synergy study of the effects of scalar NSI at various proposed Long Baseline (LBL) Experiments, viz. DUNE, T2HK and T2HKK. As the effect of scalar NSI scales linearly with environmental matter density, it can feel the matter density variations which makes LBL experiments one of the suitable candidate to probe its effects. We found that the effect of scalar NSI on the oscillation probabilities of LBL experiments is notable. In addition, scalar NSI can significantly effect the CP violation sensitivities as well as theta_{23} octant sensitivities of these LBL experiments. Finally, we have also performed a combined sensitivity of these experiments towards finding the effects of scalar NSI.