Hi, do I need to toivel a plastic bottle with a metal base? the liquid doesn’t touch the metal. Thank you!

Shalom U'vracha, Yes, it needs tevilah (immersion in a mikveh).seeing as the liquid does NOT touch the metal, and only touches the plastic part of the bottle, immerse it without saying a beracha. Sources: There is a disagreement if it is obligatory to tovel (immerse) plastic. (See Yebiah Omer 4, Yoreh Deah, 8). The custom is not to tovel plastic. If the steel just holds the plastic but doesn't touch the liquid/drink, the bottle needs tevila without a beracha (Shulchan Aruch, 120:6, Shach 12, Be'er Heitev 8). If the liquid touches the steel it will need a beracha (see Rema 120:7).