Are LHCb exotics $T_{c\bar{s}0}(2900{)}^0$, $T_{c\bar{s}0}(2900{)}^{++}$ and ${\bar{X}}_0(2900)$ members of an $S{U}_F(3)$ $\mathbf{6}$-plet?

Manifestly exotic scalar resonance $X_0(2900{)}^0$ with minimal quark content of $[\bar{c}\bar{s}ud]$ was reported by LHCb in 2020. More recently LHCb reported discovery of manifestly exotic $T_{c\bar{s}0}(2900{)}^0$ and $T_{c\bar{s}0}(2900{)}^{++}$ scalar states, degenerate with the $X_0(2900)$. We argue that these are three of six members of the flavor $SU(3{)}_F$ symmetry $\mathbf{6}$-plet. We predict the partial widths of $D(2900{)}^{\ast 0}$, the crucial non-strange missing member of the tetraquark $\mathbf{6}$-plet, and discuss the optimal decay channels for its detection.